The Canadian province of Ontario apologized for wrongly warning of an accident at a huge nuclear power plant near Toronto and blamed it for a mistake during a training.

Angry mayors called for an investigation, saying the urgent message received about the old Pickering station had caused unnecessary panic.

Ontario mobile users received a message notifying them of the alleged accident at Pickering Station and after less than an hour, the Ontario Electricity Generating Authority announced that this message was a mistake. Ontario is Canada's most populous province.

"The warning was sent to people accidentally during a routine training," Ontario State Attorney Silvia Jones said in a statement.

"The Ontario government sincerely apologizes for causing people to worry and has launched a full investigation to find out how this error occurred."